MATERNAL MENTAL HEALTH &

CHILD HEALTH AND DEVELOPMENT

Literature review of risk factors and interventions on Postpartum Depression

DEPARTMENT OF MENTAL HEALTH AND SUBSTANCE ABUSE

2008

CHAPTER 1: RISK FACTORS FOR POSTPARTUM

DEPRESSION

Emma Robertson PhD Nalan Celasun PhD

Donna E Stewart MD FRCPC

©University Health Network Women’s Health Program 2003

Citation: This chapter should be cited as: Robertson, E., Celasun, N., and Stewart, D.E. (2003). Risk factors for postpartum depression. In Stewart, D.E., Robertson, E., Dennis, C.-L., Grace, S.L., & Wallington, T. (2003). Postpartum depression: Literature review of risk factors and interventions. Contact: For further information regarding this chapter, please contact: Emma Robertson PhD at emma.robertson@uhn.on.ca or Donna E. Stewart MD FRCPC at donna.stewart@uhn.on.ca

Women’s Health Program

Financial assistance by Health Canada

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CHAPTER 1: RISK FACTORS FOR POSTPARTUM DEPRESSION

Table of Contents

LIST OF TABLES 13

LIST OF FIGURES 14

Introduction 15

Postpartum Affective Illness 15

Postpartum Period & Increased Risk of Severe Psychiatric Illness 15

Clinical Classification of Postpartum Illnesses 16

Postpartum Affective Disorders 16

Postpartum Blues 16

Postpartum Depression 17

Puerperal or Postpartum Psychosis 17

Postpartum Depression: Clinical & Diagnostic Issues 18

Prevalence 18

Clinical Presentation 19

Diagnosis 19

Defining Temporal Criteria 20

Diagnostic Definitions 21

Assessment of Depression: Clinical & Self Report Measures 22

Outcomes 23

Culture & Postpartum Depression 23

Childbirth & Culture 23

Aims of Cross Cultural Research 23

Results from Cross-Cultural Studies 24

Cultural Differences in the Presentation of Psychiatric Symptoms 24

Risk Factors for Postpartum Depression: Results from Quantitative Studies 25

Identification & Evaluation of Literature on Risk Factors for Postpartum Depression 25

Contributing Factors to Postpartum Depression 34

Multifactorial Models of Psychiatric Illness 34

Biological Factors 34

Obstetric Factors 35

Clinical Factors 37

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Psychological Factors 39

Social Factors 40

Infant Variables 46

Factors not Associated 46

Contributing Factors to the Development and Recovery from Postpartum Depression:

Metasynthesis of Qualitative Studies 52

Incongruity Between Expectations and Reality of Motherhood 52

Spiraling Downward 53

Pervasive Loss 54

Making Gains 55

Summary of Metasynthesis of Qualitative Literature 55

Summary of Risk Factors for Postpartum Depression 56

Gaps in the Literature 58

Conclusions 59

References 62

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CHAPTER SUMMARY

Introduction / Background

Postpartum non-psychotic depression is the most common complication of childbearing affecting

approximately 10-15% of women and as such represents a considerable public health problem affecting

women and their families. This chapter will provide a synthesis of the recent literature pertaining to risk

factors associated with developing this condition.

Methods

Databases relating to the medical, psychological and social science literature were searched using

specific inclusion criteria and search terms, to identify studies examining risk factors for postpartum

depression. Studies were identified and critically appraised in order to synthesize the current findings. The

search resulted in the identification of two major meta-analyses conducted on over 14,000 subjects, as well

as newer subsequent large-scale clinical studies. The results of these studies were then summarized in terms

of effect sizes as defined by Cohen.

Key Findings

The findings from the meta-analyses of over 14,000 subjects, and subsequent studies of nearly 10,000

additional subjects found that the following factors were the strongest predictors of postpartum depression:

depression during pregnancy, anxiety during pregnancy, experiencing stressful life events during pregnancy

or the early puerperium, low levels of social support and having a previous history of depression. Moderate

predictors were high levels of childcare stress, low self esteem, neuroticism and infant temperament. Small

predictors were obstetric and pregnancy complications, negative cognitive attributions, quality of

relationship with partner, and socioeconomic status. Ethnicity, maternal age, level of education, parity and

gender of child (in Western societies) were not predictors of postpartum depression.

Critical appraisal of the literature revealed a number of methodological and knowledge gaps that need to

be addressed in future research. These include examining specific risk factors in women of lower

socioeconomic status, risk factors pertaining to teenage mothers, and the use of appropriate instruments for

assessing postpartum depression in different cultural groups.

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LIST OF TABLES

Table Page

1-1. Postpartum affective disorders: Summary of onset, duration & treatment 16

1-2. Search terms used to identify relevant literature 27

1-3. Databases searched using search terms to identify literature 27

1-4. Critical appraisal guide 28

1-5. Summary of meta-analysis by O’Hara & Swain (1996) 32

1-6. Summary of meta-analysis by Beck (2001) 33

1-7. Summary of select primary studies not included by meta-analyses 48

1-8. Strong predictors of postpartum depression 60

1-9. Moderate predictors of postpartum depression 61

1-10. Small predictors of postpartum depression 61

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LIST OF FIGURES

Figure Page

1-1. DSM-IV criteria for major depressive disorder 20 1-2. Keywords, databases and years included in Beck’s meta-analysis (2001) 30

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Introduction

The postnatal period is well established as an increased time of risk for the development of serious

mood disorders. There are three common forms of postpartum affective illness: the blues (baby blues,

maternity blues), postpartum (or postnatal) depression and puerperal (postpartum or postnatal) psychosis

each of which differs in its prevalence, clinical presentation, and management.

Postpartum non-psychotic depression is the most common complication of childbearing affecting

approximately 10-15% of women and as such represents a considerable public health problem affecting

women and their families (Warner et al., 1996). The effects of postnatal depression on the mother, her

marital relationship, and her children make it an important condition to diagnose, treat and prevent

(Robinson & Stewart, 2001).

Untreated postpartum depression can have adverse long-term effects. For the mother, the episode can be

the precursor of chronic recurrent depression. For her children, a mother’s ongoing depression can contribute

to emotional, behavioral, cognitive and interpersonal problems in later life (Jacobsen, 1999).

If postpartum depression is to be prevented by clinical or public health intervention, its risk factors need

to be reliably identified, however, numerous studies have produced inconsistent results (Appleby et al.,1994;

Cooper et al., 1988; Hannah et al.,1992; Warner et al., 1996). This chapter will provide a synthesis of the

recent literature pertaining to risk factors associated with developing this condition.

Postpartum Affective Illness

Postpartum Period & Increased Risk of Severe Psychiatric Illness

The association between the postpartum period and mood disturbances has been noted since the time of

Hippocrates (Miller, 2002). Women are at increased risk of developing severe psychiatric illness during the

puerperium. Studies have shown that a woman has a greatly increased risk of being admitted to a psychiatric

hospital within the first month postpartum than at any other time in her life (Kendell et al.,1987;

Paffenbarger, 1982). Up to 12.5% of all psychiatric hospital admissions of women occur during the

postpartum period (Duffy, 1983).

However recent evidence from epidemiological and clinical studies suggests that mood disturbances

following childbirth are not significantly different from affective illnesses that occur in women at other

times. Population based studies in the USA and the United Kingdom, for instance, have revealed similar

rates of less severe depressive illness in puerperal and nonpuerperal cohorts (Cox et al.,1993; Kumar &

Robson, 1984; O'Hara et al.,1991a). Also, the clinical presentation of depression occurring in the puerperium

is similar to major depression occurring at other times, with symptoms of depressed mood, anhedonia and

low energy and suicidal ideation commonplace.

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Clinical Classification of Postpartum Illnesses

There has long been controversy as to whether puerperal illnesses are separate, distinct illnesses

(Hamilton, 1982; Hays & Douglass, 1984; Hays, 1978) or episodes of a known psychiatric disorder such as

affective disorders or schizophrenic psychoses, which occur coincidentally in the puerperium or are

precipitated by it (Platz & Kendell, 1988; Robling et al., 2000).

Brockington (1988) argues that childbirth should be seen as a general stressor, like any other ‘life event’

which can trigger an attack of illness across the whole spectrum of psychiatric disorders. This view is now

generally accepted and is supported by the wide variety of clinical disorders which follow childbirth, and the

variety of symptoms which are found in illnesses which start after delivery.

Postpartum Affective Disorders

Postpartum affective disorders are typically divided into three categories: postpartum blues,

nonpsychotic postpartum depression and puerperal psychosis.

The prevalence, onset and duration of the three types of postpartum affective disorders are shown in

Table 1-1 (Adapted from Nonacs & Cohen, 1998). Each of them shall be discussed briefly.

Table 1-1. Postpartum Affective Disorders: Summary of Onset, Duration & Treatment

Disorder Prevalence Onset Duration Treatment

Blues 30 – 75% Day 3 or 4 Hours to days No treatment required other than reassurance

Postpartum Depression

10 – 15% Within 12 months Weeks – months Treatment usually required

Puerperal Psychosis 0.1 – 0.2 % Within 2 weeks Weeks - months Hospitalization usually required

Postpartum Blues

Postpartum blues is the most common observed puerperal mood disturbance, with estimates of

prevalence ranging from 30-75% (O'Hara et al., 1984). The symptoms begin within a few days of delivery,

usually on day 3 or 4, and persist for hours up to several days. The symptoms include mood lability,

irritability, tearfulness, generalized anxiety, and sleep and appetite disturbance. Postnatal blues are by

definition time-limited and mild and do not require treatment other than reassurance, the symptoms remit

within days (Kennerly & Gath, 1989; Pitt, 1973).

The propensity to develop blues is unrelated to psychiatric history, environmental stressors, cultural

context, breastfeeding, or parity (Hapgood et al.,1988), however, those factors may influence whether the

blues lead to major depression (Miller, 2002). Up to 20% of women with blues will go on to develop major

depression in the first year postpartum (Campbell et al., 1992; O'Hara et al., 1991b).

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Postpartum Depression

As the focus of this chapter is postpartum depression, only a brief overview shall be provided here. Data

from a huge population based study showed that nonpsychotic postpartum depression is the most common

complication of childbearing, occurring in 10-15% of women after delivery (O'Hara & Swain, 1996). It

usually begins within the first six weeks postpartum and most cases require treatment by a health

professional.

The signs and symptoms of postpartum depression are generally the same as those associated with major

depression occurring at other times, including depressed mood, anhedonia and low energy. Reports of

suicidal ideation are also common.

Screening for postnatal mood disturbance can be difficult given the number of somatic symptoms

typically associated with having a new baby that are also symptoms of major depression, for example, sleep

and appetite disturbance, diminished libido, and low energy (Nonacs & Cohen, 1998). Whilst very severe

postnatal depressions are easily detected, less severe presentations of depressive illness can be easily

dismissed as normal or natural consequences of childbirth.

Puerperal or Postpartum Psychosis

Very severe depressive episodes which are characterized by the presence of psychotic features are

classed as postpartum psychotic affective illness or puerperal psychosis. These are different from postpartum

depression in aetiology, severity, symptoms, treatment and outcome.

Postpartum psychosis is the most severe and uncommon form of postnatal affective illness, with rates of

1 – 2 episodes per 1000 deliveries (Kendell et al., 1987). The clinical onset is rapid, with symptoms

presenting as early as the first 48 to 72 hours postpartum, and the majority of episodes developing within the

first 2 weeks after delivery. The presenting symptoms are typically depressed or elated mood (which can

fluctuate rapidly), disorganized behaviour, mood lability, and delusions and hallucinations (Brockington et

al., 1981). Follow-up studies have shown that the majority of women with puerperal psychosis meet criteria

for bipolar disorder (Brockington et al., 1981; Dean & Kendell, 1981; Kendell et al., 1987; Klompenhouwer

& van Hulst, 1991; Kumar et al., 1995; Meltzer & Kumar, 1985; Okano et al., 1998; Robling et al., 2000;

Schopf et al., 1984).

Research evidence has shown that risk factors for puerperal psychosis are biological and genetic in

nature (see Jones et al., 2001). Psychosocial and demographic factors are probably not major factors in the

development of puerperal psychosis (Brockington et al., 1990; Dowlatshahi & Paykel, 1990).

Compelling evidence from recent studies of puerperal psychosis suggest that the major risk factor for

developing the illness is genetic. Jones & Craddock (2001) found that the rate of puerperal psychosis after

deliveries in women with bipolar disorder was 260 / 1000 deliveries, and the rates of puerperal psychosis for

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women with bipolar disorder who also had a family history of puerperal psychosis was 570 / 1000 deliveries.

This compares to a risk in the general population of 1-2 / 1000 deliveries.

Due to the nature of psychotic or depressive symptoms, new mothers are at risk of injuring their children

through neglect, practical incompetence or command hallucinations or delusions (Attia et al.,1999).

Infanticide is rare, occurring in 1-3 / 50,000 births (Brockington & Cox-Roper, 1988; Jason et al.,1983),

however, mothers with postpartum psychotic disorders commit a significant percentage of these, and

estimates suggest that 62% of mothers who commit infanticide also go on to commit suicide (Gibson, 1982).

Because of these serious consequences, early diagnosis and treatment interventions of postnatal illnesses are

imperative for the health and well being of the mother and child (Attia et al., 1999).

Puerperal psychosis requires hospitalization for treatment (Nonacs & Cohen, 1998). Although the

prognosis is generally favourable and women fully recover they are at risk of developing further puerperal

and nonpuerperal episodes of bipolar affective disorder (Reich & Winokur, 1970; Schopf et al., 1984).

Postpartum Depression: Clinical & Diagnostic Issues

Postpartum depression is the most common complication of childbearing and as such represents a

considerable public health problem affecting women and their families (Warner et al., 1996). The effects of

postnatal depression on the mother, her marital relationship, and her children make it an important condition

to diagnose, treat and prevent (Robinson & Stewart, 2001).

Untreated postpartum depression can have adverse long term effects. For the mother, the episode can be

the precursor of chronic or recurrent depression. For her children, a mother’s ongoing depression can

contribute to emotional, behavioral, cognitive and interpersonal problems in later life (Jacobsen, 1999).

If postpartum depression is to be prevented by clinical or public health intervention, its risk factors need

to be reliably identified, however, numerous studies have produced incomplete consensus on these (Warner

et al., 1996; Cooper et al., 1988; Hannah et al., 1992). The remainder of this chapter will provide a synthesis

of the recent literature pertaining to risk factors associated with developing the illness.

Prevalence

O’Hara & Swain (1996) in a meta analysis of 59 studies from North America, Europe, Australasia and

Japan (n=12,810 subjects), found an overall prevalence rate of postpartum depression of 13%. This was

based on studies that assessed symptoms after at least two weeks postpartum (to avoid confounding of

postpartum blues) and used a validated or standardized measure to assess depression.

Maternal Age

It should be noted that the literature pertains to adult women of 18 years and older. Research which has

examined the rates of postpartum depression in mothers aged 14 - 18 years (n=128) showed a much higher

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rate of illness, approximately 26% (Troutman & Cutrona, 1990). However, within this younger population

there may be risk factors which predispose not only to postpartum depression, but also to pregnancy during

adolescence and therefore are not independent risk factors for postpartum depression. This is a population

which requires further research to establish specific risk factors.

Clinical Presentation

Postpartum depression usually begins within 1–12 months after delivery. In some women, post partum

blues simply continue and become more severe. In others, a period of wellbeing after delivery is followed by

a gradual onset of depression. The patterns of symptoms in women with postpartum depression are similar to

those in women who have depression unrelated to childbirth (Wisner, Parry, & Piontek, 2002), apart from the

fact that the content may focus on the delivery or baby. Evidence from epidemiological and clinical studies

suggests that mood disturbances following childbirth are not significantly different from affective illnesses

that occur in women at other times (Cox et al., 1993; Kumar et al., 1984; O'Hara et al., 1991a) .

Postpartum depression is characterized by tearfulness, despondency, emotional lability, feelings of guilt,

loss of appetite, and sleep disturbances as well as feelings of being inadequate and unable to cope with the

infant, poor concentration and memory, fatigue and irritability (Robinson et al., 2001). Some women may

worry excessively about the baby’s health or feeding habits and see themselves as ‘bad’, inadequate, or

unloving mothers (Robinson et al., 2001).

Diagnosis

There are two main classification systems used within psychiatry: The American Psychiatric

Association’s Diagnostic & Statistical Manual of Mental Disorders now in its fourth edition (DSM-IV, 1994)

and the 10th edition of the International Classification of Diseases, (ICD-10), published by the World Health

Organization (World Health Organization, 1993).

The DSM-IV (American Psychiatric Association, 1994) and ICD-10 (World Health Organization, 1993)

contain standardized, operationalized diagnostic criteria for known mental disorders, and are used globally to

diagnose patients within clinical and research settings. The Research Diagnostic Criteria (RDC), (Spitzer,

Endicott, & Robins, 1978) is also commonly used within research studies as a means of classifying

psychiatric disorders.

As previously stated, the literature suggests that postpartum mood disturbances do not differ

significantly from affective illnesses that occur in women at other times (Cox et al., 1993; Kumar et al.,

1984; O'Hara et al., 1991a; O'Hara et al., 1991b).

At present, postpartum depression is not classified as a separate disease in its own right: it is diagnosed

as part of affective or mood disorders in both DSM-IV (American Psychiatric Association, 1994) and ICD-

10 (World Health Organization, 1993). Within DSM-IV there is a specifier ‘with postpartum onset’ to

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identify affective or brief psychotic episodes that occur during the postpartum period: an episode is specified

as having a postpartum onset if it occurs within the first 4 weeks after delivery (American Psychiatric

Association, 1994). Similarly in ICD-10, the episode must be diagnosed within a main diagnostic category

with the specifier to indicate the association with the puerperium (World Health Organization, 1993).

The symptoms required to meet DSM-IV criteria for a major depressive episode are shown in Figure 1-

1.

Figure 1-1. DSM-IV Criteria for Major Depressive Disorder

Criteria for Major Depressive Episode

Five (or more) of the following symptoms have been present during the same 2-week period and represent a change from previous functioning; at least one of the symptoms is either (1) depressed mood or (2) loss of interest or pleasure. Note: Do not include symptoms that are clearly due to a general medical condition, or mood-incongruent delusions of hallucinations.

Depressed mood most of the day, nearly every day, as indicated by either subjective report (e.g. feels sad or empty) or observation made by others (e.g. appears tearful)

Markedly diminished interest or pleasure in all, or almost all, activities most of the day, nearly every day (as indicated by either subjective account or observation made by others)

Significant weight loss when not dieting or weight gain (e.g. a change of more than 5% of body weight in a month), or decrease or increase in appetite nearly every day

Insomnia or hypersomnia nearly every day Psychomotor agitation or retardation nearly every day (observable by others, not merely subjective

feelings of restlessness or being slowed down) Fatigue or loss of energy nearly every day Feelings of worthlessness or excessive or inappropriate guilt (which may be delusional) nearly every

day (not merely self-reproach or guilt about being sick) Diminished ability to think or concentrate, or indecisiveness, nearly every day (either by subjective

account or as observed by others) Recurrent thoughts of death (not just fear of dying), recurrent suicidal ideation without a specific plan,

or a suicide attempt or a specific plan for committing suicide The symptoms do not meet criteria for a Mixed Episode The symptoms cause clinically significant distress or impairment in social, occupational, or other

important areas of functioning The symptoms are not due to the direct physiological effects of a substance (e.g. a drug of abuse, a

medication) or a general medical condition (e.g. hypothyroidism) The symptoms are not better accounted for by Bereavement, i.e. after the loss of a loved one, the

symptoms persist for longer than 2 months or are characterized by marked functional impairment, morbid preoccupation with worthlessness, suicidal ideation, psychotic symptoms or psychomotor retardation.

Postpartum onset specifier: Onset of episode within 4 weeks postpartum

Defining Temporal Criteria

An obvious limitation of the temporal criteria used within DSM-IV is that it excludes all cases which

have an onset later than 4 weeks postpartum. This has implications for establishing accurate prevalence rates

of the illness, as cases with an onset later than 4 weeks could not easily be identified as being related to

childbirth in many studies.

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The maximum time interval used to define the puerperal period differs among studies. Some authors e.g.

Paffenbarger (1982), Arentsen (1968) defined puerperal illness as any illness leading to hospital admission

within 6 months of delivery. Others, like Brockington et al. (1982) have argued that the time interval should

be restricted to illnesses starting within 2 or 3 weeks of delivery. Kendell et al. (1987) argued that if the onset

criteria is hospital admission or contact, a cut-off point of 90 days is the most appropriate.

Based on the results of epidemiological studies, the time frame most commonly used to specify a

postpartum onset within research studies ranges from 3 months (Kendell et al., 1987) to up to 12 months

after delivery (Miller, 2002). This is to ensure that all cases of postpartum depression are included within

research studies to provide accurate information on the clinical and diagnostic aspects of the illness.

Diagnostic Definitions

The term ‘postpartum depression’ refers to a nonpsychotic depressive episode that begins in the

postpartum period (Cox et al., 1993; O'Hara, 1994; Watson et al.,1984).

In past research, these depressions have been defined in a number of ways (O'Hara & Zekoski, 1988)

however, more recent and rigorous studies have defined postpartum depression based on standardized

diagnostic criteria for depression including DSM-IV (American Psychiatric Association, 1994) ICD-10

(World Health Organization, 1993) and RDC .

As previously stated, screening for postnatal mood disturbance can be difficult given the number of

somatic symptoms typically associated with having a new baby that are also symptoms of major depression

(Nonacs et al., 1998). Distinguishing between depressive symptoms and the supposed ‘normal’ sequelae of

childbirth, such as changes in weight, sleep, and energy is a challenge that further complicates clinical

diagnosis (Hostetter & Stowe, 2002).

For example, although it is difficult to assess sleep disturbance in new mothers, the clinician may ask

about the mother’s ability to easily rest or sleep when given the opportunity. Many women with postpartum

depression often have such high levels of anxiety that they are unable to rest or return to sleep after getting

up with the infant at night.

Postpartum alterations in body weight are highly variable and it is important to ask about a woman’s

‘desire for food’ and ‘whether food tastes good’. The issue of libido should be expanded to include the

acceptance of affection.

Further confounding the determination of postpartum depression is the presence of possible physical

causes (including anemia, diabetes, and thyroid dysfunction) that could potentially contribute to depressive

symptoms (Pedersen et al., 1993).

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Assessment of Depression: Clinical & Self Report Measures

Historically several types of outcome measures of depression have been used, however, more recent

studies use standardized measures, assessed by clinical interview or self-report (O'Hara et al., 1988).

Semistructured clinical interviews based on diagnostic research criteria allow the elicitation of

psychopathological symptoms in order to generate diagnoses. The use of standardized interviews increases

the reliability of diagnoses between researchers, and allows researchers to establish and assess the severity of

symptoms, through probing questions. The financial and time costs associated with performing face-to-face

interviews however restrict their use to a limited number of subjects usually within a research study.

Self-report measures are easier and cheaper to administer and do not require the presence of specifically

trained clinicians, thereby enabling a larger sample to be studied. While self-report measures have the

advantage of objectivity, they are usually designed to provide diagnostic information. The measures have a

‘threshold’ or ‘cut off’ score, which usually indicates that the individual meets symptom criteria for being

considered a ‘case’ (of postpartum depression in this example).

However, the practice of using a ‘cut off’ score on a rating scale such as the Beck Depression Inventory

(BDI) or the General Health Questionnaire (GHQ), to identify women with postpartum depression can lead

to misclassification. High scores on such measures may reflect factors other than depression, including

physical ill health. For example, the BDI has many items that would be expected to give elevated scores even

in the course of a normal pregnancy or puerperium e.g. fatigue, body image, sleep disturbance, loss of libido.

In making a diagnosis of depression, the length of time that the symptoms have been present and the

extent to which the symptoms interfere with the woman’s usual functioning are pertinent. These

considerations are rarely addressed in self-report measures.

In order to address some of these issues, rating scales have been developed specifically for use within a

postnatal population. The most well established is the Edinburgh Postnatal Depression Rating Scale (EPDS),

a 10 item self rated measure that has been translated into more than a dozen languages and is highly

correlated with physician rated depression measures (Cox, Holden, & Sagovsky, 1987).

Using the EPDS women who exceed a threshold score of 10 (within family practices) and 12 (within

research studies) have a greater likelihood of being depressed (Cox et al., 1987).

Even though women who are classified as depressed on the basis of a self-report measure may not meet

criteria for syndromal depression – e.g. using DSM-IV criteria, they often experience significant personal

distress and social morbidity (Johnson, Weissman, & Klerman, 1992; Wells et al., 1989).

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Outcomes

The majority of postnatal depressions are self limiting, resolving within months of onset (Kumar et al.,

1984; Watson et al., 1984). However, for many women childbirth is the stressor which triggers the start of

recurrent or chronic episodes of depressive disorder.

Women who have experienced postpartum depression are at risk of suffering further episodes of illness,

both following subsequent deliveries and also unrelated to childbirth (Kumar et al., 1984; Philipps & O'Hara,

1991; Nott, 1987; Warner et al., 1996). After one postpartum episode the risk of recurrence, defined as an

episode of illness meeting criteria for DSM-IV major depression, is 25% (Wisner et al., 2002).

Culture & Postpartum Depression

Childbirth & Culture

With a few notable exceptions, most of the relevant research into psychiatric disorders associated with

childbearing has been confined to developed countries, mainly in Western Europe and North America

(Kumar, 1994).

The physiology of human pregnancy and childbirth is the same all over the world, but the event is

conceptualized and structured, and hence, experienced by the mother and by her social group very differently

(Kumar, 1994). It has been purported that postpartum depression simply does not exist within certain

cultures. Stern and Kruckman (1983) wrote that a review of the anthropological literature revealed

surprisingly little evidence of the phenomenon identified in Western diagnoses as postnatal depression.

This conclusion was lent some support by anecdotal observations in Nigeria (Kelly, 1967), South Africa

(Chalmers, 1988) and India (Gautam, Nijhawan, & Gehlot, 1982) that nonpsychotic depression after

childbirth is rare in such societies. However, higher maternal morbidity rates may result in under-reporting.

It should be noted that these conclusions were based on observational data, and not all studies combined

ethnographic field observations with formal diagnostic testing. One should also be aware of the danger of

cultural stereotyping, and of the possibility that the presence of disorders such as postpartum depression in

particular cultures may go unrecognized (Kumar, 1994).

Aims of Cross Cultural Research

Stern and Kruckman (1983) draw attention to the fact that the defining criteria for depression may vary

greatly across different cultural settings, so the problem cannot simply be resolved by applying a Western

concept of depression to other cultures.

One of the primary aims of cross-cultural comparative research is to examine whether there are

differences in clinical presentation in different settings. Cox (1999) discussed the presentation of ‘Amikiro’

in Ugandan women; where women express the urge to eat their baby. Whilst Western clinical interviews do

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not specifically question women about their desire to eat their baby, through careful questioning, as in semi

structured interviews, it would be possible to detect psychological dysfunction in cultural and ethnic settings

in which it has been suggested that postpartum depression does not occur.

Similarly, it is important to try to find out whether observed differences in childrearing practices have a

mitigating or an exacerbating influence on the possible adverse effects of maternal postnatal illness on the

child’s psychological development.

Results from Cross-Cultural Studies

Large scale studies comparing rates of postnatal depression across cultures have found similar rates to

those reported in Western Europe and North America. Cox’s (1983) Ugandan study has shown that African

mothers become depressed at a similar rate to those in developed nations. Dennerstein et al. (1989) and

Thorpe et al. (1992) have found similar rates of depression after childbirth in comparisons of Australian,

Italian and Dutch mothers and of Greek and English mothers, respectively. Jadresic et al. (1992) reported

similar prevalence rates in Chilean women, and Shah et al. (1971) found that a quarter of women attending a

well baby clinic in India were diagnosed as suffering from “neurotic disorders with a post-partum onset”

(and hence likely to be depressive disorders).

One does need to consider the possible limitations of using existing assessment tools within different

ethnic groups. For example, Watson & Evans (1986) compared three ethnically different groups of

childbearing women using the General Health Questionnaire (GHQ). They found that some questions e.g.

‘have you ever felt that life isn’t worth living’ were perceived as meaningless by Bengali mothers who could

not conceive of such a possibility.

Cultural Differences in the Presentation of Psychiatric Symptoms

It is well established that there are marked cultural differences in the way that psychiatric symptoms are

presented to health professionals (Kleinman, 1996) with some groups more likely to somatize symptoms.

Upadhyaya et al. (1989) found no marked differences in rates of depression or level of somatic and

psychological symptoms between groups of indigenous white and Asian women presenting to clinics in

India. However, when their reasons for consulting their doctors were examined, the Asian women consulted

exclusively for somatic symptoms whereas the white mothers were more likely to present with depression.

This may be linked into women’s reluctance to admit to symptoms of depression because of cultural

expectations of motherhood.

The rituals adopted within some cultures following childbirth have been purported to protect against the

development of postpartum depression. For example, Okano et al. (1992) have drawn attention to the

Japanese custom of Satogaeri Bunben in which the new mother stays with her own mother for several weeks

after giving birth. They have suggested that there may be a link between the onset of depression and having

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to leave the maternal home. Therefore a perceived, or actual, lack of social support may contribute to the

onset of the illness.

Summary

There are no major differences in the rates of postnatal depression in the few cross-cultural comparisons

that have so far been reported. Differences rather than similarities in incidence rates might have been

expected and these important studies need replication and extension in other settings.

Some of the rituals practiced within cultures may be protective against postnatal depression because

they provide social and practical support for the new mother.

Psychiatric disorders are heavily stigmatized within many cultures, and women and their families may

be reluctant to seek help from health professionals, preferring to try and manage the illness with no outside

help. Health professionals may only be consulted when the woman is so severely ill that the family can no

longer cope.

The use of standardized assessment tools may not be culturally relevant within certain ethnic groups;

there may also be reluctance to discuss issues such as libido or feelings of self-harm as they are deemed

inappropriate to be discussed outside of the family.

Risk Factors for Postpartum Depression: Results from Quantitative Studies

Variables which have been investigated as potential risk factors for postpartum depression will be

presented and discussed; the results from studies using quantitative and qualitative methods will be presented

and discussed separately.

Identification & Evaluation of Literature on Risk Factors for Postpartum Depression

The literature on postpartum depression is vast: in order to identify articles of good quality which

reported risk factors for postpartum depression, the following criteria were devised:

Initial Inclusion & Exclusion Criteria

1. Precise definition of postpartum depression stated.

Studies had to clearly describe both the diagnostic and temporal criteria of postpartum depression

used. The diagnoses must have been made according to standard operational diagnostic criteria such

as RDC, DSM-IV or ICD-10, and the onset of the illness must have been within one year of

parturition. This temporal definition ensured that all studies pertaining to depression related to

childbirth were included. Only cases of nonpsychotic depression were included.

2. Method of Assessment for Postpartum Depression Specified.

26

Studies had to specify both the means of assessment for postpartum depression i.e. self-report or clinical

interview and the instrument used i.e. the name of questionnaire or interview. These measures needed to

have proven reliability and validity.

3. Human studies

4. The study must be empirical and not merely anecdotal evidence or narrative.

5. English language

6. Studies published from 1990 – 2002 (seminal studies conducted prior to 1990 identified through key

references, general reading and authors’ expertise in area were also included)

7. Timing of Assessment.

The timing of the assessment of depression must have been clearly stated and be greater than 2 weeks

postpartum to avoid the reporting of postpartum blues.

8. Definition of Risk Factors.

The variables of interest were defined and measured using appropriate methods. The statistical

relationship between the variable and postpartum depression was clearly stated.

Search & Retrieval Strategies

Online searching of databases

Based on advice from Marina Englesakis (MLIS) an Information Specialist in Libraries & Information

Services at the University Health Network, we used 20 keywords and employed sophisticated search term

strategies including mapping to subject headings and truncation of keywords to include all variants in order

to identify all relevant literature.

As researchers from different national backgrounds we are acutely aware of different uses of

terminology between North America and Europe (for example, postpartum, postnatal, maternal or puerperal

depression). We ensured that all terms in common use to describe depression in the postpartum period were

included.

The search terms and databases used to identify potential studies of interest are shown in Tables 1-2 and

1-3. In order to retrieve pertinent studies limits were placed on the search:

Published from 1990 – 2002

English language

Human studies

27

Table 1-2. Search terms used to identify relevant literature

postpartum depress:.mp. post partum depress:.mp postnatal depress:.mp. post natal depress:.mp. baby blues postpartum blues post partum blues depression, postpartum postpartum dysthymia post partum dysthymia puerperal disorders puerperal psychosis postpartum psychosis post partum psychosis risk factors contribute:.mp. prevent:.mp. protect:.mp. protective factors perinatal depression

Table 1-3. Databases searched using search terms to identify relevant literature

Medline PsychInfo CINAHL- Cumulative Index to Nursing and Allied Health Literature

Campbell Collaborative Reviews

EMBASE- Evidence-Based Medicine DARE- Database of Abstracts of Reviews of Effectiveness

CDSR-Cochrane Database of Systematic Reviews Dissertation Abstract International CCTR- Cochrane Controlled Trials Register Evidence Based Medicine Reviews-American College

of Physicians Journal Club ProQuest Web of Science HealthStar Social Science Citation Index U.K. Department of Health Research National Health Register WHO Reproductive Health Library PubMed CDC-MMWR(Centers for Disease Control and Prevention-Morbidity and Mortality Weekly Report)

The initial search results generated over 946 potential studies. Excluding duplicates and applying the

inclusion criteria, a total of 137 studies were identified and retrieved.

Although a search of unpublished or ‘grey’ literature was conducted, when the inclusion criteria were

applied and likely papers reviewed it was determined that they did not contribute to the existing published

literature. Therefore only studies published in peer-reviewed journals were retrieved.

Although the database searches should have identified all recent papers, for completeness the tables of

contents in 42 key journals within the area, for the last two years were searched, to ensure that suitable

papers had not been omitted (see Appendix C). No additional relevant studies were found.

Assessment of Quality

Our strategy for critically appraising retrieved articles incorporated standard procedures, as shown in

Table 1-4.

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Table 1-4. Critical Appraisal Guide

An assessment of the quality, relevance and contribution of the study to existing literature The scientific rigour and appropriateness of the research study design Sampling methods used to identify and recruit subjects How postpartum depression was measured i.e. self report or diagnostic interview The reliability and validity of the instrument used to measure postpartum depression The timing of the assessment for depression i.e. was it long enough after delivery to exclude assessing ‘baby blues’ Evaluation of bias throughout the research process Evaluation of statistical methods including data collection, use of statistical tests and reporting of data Appropriateness of conclusions and recommendations drawn from the study

Interpretation & Analysis of Data

Meta Analyses of Risk Factors for Postpartum Depression

The literature search identified two recent meta-analyses of risk factors for postpartum depression which

had been conducted by O’Hara & Swain (1996) and Beck (2001). The Beck paper was a follow-up to a

previous meta-analysis published in 1996. Due to the importance of these two papers, a discussion of their

methodologies and inclusion criteria will follow.

O’Hara & Swain (1996) stated that the main purpose of undertaking the meta-analysis was to quantify

the relationships between postpartum depression (defined on the basis of depression severity or diagnosis)

and a variety of non-biological or hormonal risk factors.

A meta-analytic approach allows the investigator to summarize, in a quantitative fashion, the results of

disparate studies. It yields an effect size that describes the strength of a relationship between two variables

that were obtained in at least two independent studies.

Effect sizes may vary from 0 (zero), which indicates a random relationship, to numbers greater than 1.

Effect sizes within the meta-analytic studies of O’Hara & Swain (1996) and Beck (2001) are reported in

terms of Cohen’s d, with a d of 0.2 indicating a small relationship, 0.4 indicating a moderate relationship and

0.8 indicating a strong relationship (Cohen, 1977). In the postpartum depression literature effect sizes usually

are in the order of 0.2 to 0.5, ‘small to medium’ effect sizes according to Cohen (1977).

A second yield from a meta-analysis is a confidence interval, usually a 95% confidence interval. This

confidence interval describes the range in which the ‘true’ population effect size lies, with 95% confidence.

Finally, it is often noted that there is considerable heterogeneity in effect sizes across investigations.

Sometimes this heterogeneity can be explained by specific variables that differ across the studies such as

different methods used to assess depression or the country in which the study was conducted.

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Analysis of New Data within the Context of Published Meta-Analyses

Our search and retrieval strategy allowed us to identify studies that had previously been identified and

included in the two meta-analyses, studies that had been conducted or published subsequent to the meta-

analyses, and those that had not been included by Beck (2001) or O’Hara & Swain (1996).

Table 7 at the end of the chapter summarizes the results of a selection of primary studies not included in

the meta-analyses. These studies have been highlighted because they add to the literature in distinct ways.

There are a number of large scale studies in which there was adequate power to detect effects (e.g. Forman et

al.,2000; Warner et al.,1996). Other studies had employed systematic consecutive sample recruitment which

reduce the risk of bias (e.g. Johnstone et al.,2001). Data were also obtained from samples in which there is a

dearth of work, for example diverse cultural groups including Chinese (Lee et al.,2000) and Indian (Patel et

al., 2002) women.

The results of these new studies were analyzed in relation to the findings of the meta-analyses. Due to

the power of the meta-analyses to detect effects we could comment on whether the newer studies supported

the findings of the meta-analyses or whether the interpretation of the contributing factors should be changed

as a result of new evidence. For the purposes of this chapter non-significance was defined as the confidence

interval containing 0. A summary of the findings of the meta-analyses, and the findings of newer studies are

provided in Tables 8 – 10 at the end of the chapter.

It is important, therefore, to be aware of the content of the two meta-analyses, each of which shall be

discussed in turn.

Summary of Published Meta-Analyses

Beck 2001: Summary of Criteria & Methods

The search and retrieval strategies employed by Beck were based on Cooper’s (1989) five approaches:

1. The ancestry and descendancy approach (i.e. ways of checking prior and subsequent publications

from the reference lists in articles)

2. Online computer searching (see table below)

3. Informal contacts at professional research conferences and

4. Abstracting services

5. The keywords used to search, limitations on articles retrieved and the databases these terms were

used in are shown below in Figure 1-2.

30

Figure 1-2. Keywords, databases and years included in Beck’s meta-analysis (2001)

Databases Searched by Beck Limits Keywords CINAHL Medline Psych Info Eric Popline Social Work Abstract Sociological Abstracts Dissertation abstracts JREF

Articles published between 1990 – 1999

“postpartum depression” “postnatal depression” “puerperal depression” “predictors AND risk factors”

In order to be included in the meta-analysis studies had to meet the following criteria:

• The study assessed the relationship between postpartum depression and predictor variables

• The mood disorder was measured after 2 weeks postpartum to comply with DSM-IV (American

Psychiatric Association, 1994) diagnostic criteria and also to avoid measuring blues inadvertently

• Adequate statistics were present in the results to allow meta analytic calculations

• If an F or χ 2 statistics was used to analyze data, a degree of freedom of 1 was necessary to avoid

unfocused, general comparisons between several means.

Beck identified a total of 84 studies which met her inclusion criteria. The methodological quality of each

paper was assessed in terms of:

• Sampling methods

• How postpartum depression was measured i.e. self report or diagnostic interview

• The reliability and validity of the instrument used to measure postpartum depression

• Research design

• Timing of the assessment for postpartum depression

• Data analysis

O’Hara and Swain 1996: Summary of Criteria & Methods

O’Hara and Swain gave details of their inclusion criteria but did not explicitly state their retrieval

strategies. In order to be included in O’Hara and Swain’s analyses, the study had to fulfill the following

criteria:

• A reported statistical relationship between the variable of interest and postpartum depression.

• The variable of interest was assessed either during pregnancy or delivery.

• Subjects were recruited through random or quasi-random sampling techniques.

• Depression was assessed after at least two weeks postpartum (to avoid confounding of postpartum

blues).

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• Postpartum depression was assessed using a validated or standardized measure.

O’Hara and Swain identified a total of 77 studies which met their inclusion criteria.

Evaluation of the studies

Although the identification and retrieval strategies for the meta-analyses appear similar, there are

differences that may result in differing scientific quality of the papers retrieved. The databases included in

Beck’s search (ibid) are more obscure and return higher numbers of unpublished work and dissertations.

With few exceptions, the studies identified by O’Hara and Swain (ibid) had all been published in peer-

reviewed journals and subjected to methodological and statistical review. Within Beck’s meta-analysis (ibid)

a number of less rigorous definitions of concepts were used, for example, ‘life stress’ rather than objective

measures of ‘life events’. Similarly, a number of factors were examined which were measured postpartum

and be reflective of the mother’s depressed mood, including self-esteem and measures of child temperament.

It was on occasion unclear which measures or questionnaires had been used and whether there were

differences in scores depending on which measure had been used. O’Hara and Swain (ibid) explicitly stated

and differentiated between measures used within studies and commented for each variable on the

heterogeneity of study results.

Therefore, more weight would be given to the findings of O’Hara and Swain due to the more rigorous

analytical methods used, and the confidence with which the results can be interpreted based on the detail

provided on methods of assessment, sample size and differences between countries or cultures.

A summary of each of the studies are shown in Tables 1-5 and 1-6, including the number of studies and

subjects included, where the studies were conducted, the variables examined and their significance as well as

limitations and comments on the studies.

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Table 1-5. Summary of Meta-Analysis by O’Hara and Swain (1996)

Number of Studies

& Subjects

Where Studies

Conducted

Variables Examined

Effect Size Level Comments

Sociodemographic

Non-significant

Clinical Factors Depression during pregnancy Prenatal anxiety Previous history of depression Family history of depression

Moderate/Strong Moderate Moderate No association

Obstetric & Infant Related Factors Obstetric & Pregnancy complications

Small

Psychological Factors Cognitive attributions Neuroticism

Small Moderate

77 Studies 12, 210 Subjects

Europe N. America Asia Japan Australasia

Social Factors Life events Social support Marital status Marital relationship (DYAS) Income

Moderate Moderate No association Small Small

Very well designed meta-analysis Well powered to detect effect sizes All factors measured antenatally so higher predictive power All studies used standardized instruments to measure risk factors High number of studies used clinical interviews for diagnosis Limitation: 3 / 77 studies were unpublished

33

Table 1-6. Summary of Meta-Analysis by Beck (2001)

Number of Studies

& Subjects

Where Studies

Conducted Variables Examined Effect size

Level Limitations

Clinical Factors Depression during pregnancy Prenatal anxiety Maternity blues Previous history of depression

Moderate Moderate Small Moderate

Obstetric & Infant Related Factors Unplanned / unwanted pregnancy Childcare stress Infant temperament

Small Moderate Moderate

Psychological Factors Self-esteem

Moderate

84 Studies Approx. 3000 Subjects

Europe N. America S. America Asia Japan Australasia Africa Middle East China

Social Factors Life stress Social support Marital status Marital relationship Socioeconomic status

Moderate Moderate Small Moderate Small

30 / 84 unpublished studies Unable to calculate accurate sample size due to high number of unpublished studies Factors measured postpartum may be influenced by mother’s depressed mood Could not establish which instruments or measures had been used for some variables Some factors may reflect mood state i.e. self-esteem, reports of child behaviour Few studies used clinical interviews to diagnose depression Cannot establish whether there are differences in scores when different instruments used Less rigorous definitions of concepts used compared to O’Hara & Swain

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Contributing Factors to Postpartum Depression

Multifactorial Models of Psychiatric Illness

When interpreting studies of aetiological factors of psychiatric illness, it important to remember that it is

highly likely that there is no one single cause. Genetic and biological studies of mood disorders indicate that

they are complex diseases, and even if an individual has a genetic vulnerability or predisposition to

developing depression, there have to be experiential and environmental factors which interact to cause the

illness (Dubovsky & Buzan, 1999). Therefore, it is likely that a number of these factors play a role in the

development of postpartum depression.

Biological Factors

Although the focus of the meta-analyses focused on non-biological risk factors it is necessary to provide

an overview of biological theories of postpartum depression.

The rapid decline in the levels of reproductive hormones that occur after delivery has been proposed as a

possible aetiology of postpartum affective disorders (Wisner et al., 2002). Following childbirth, progesterone

and estrogen levels fall rapidly, returning to prepregnancy levels within 3 days. When estrogen falls after

birth, prolactin, which has risen during pregnancy, is no longer blocked and lactation is initiated. Suckling by

the infant stimulates the secretion of oxytocin. The usual cyclical variation of androgens is absent during

both pregnancy and lactation. Plasma corticosteroids reach a peak during labour and decrease significantly

within 4 hours postpartum. Thyroid function returns to prepregnancy levels approximately 4 weeks after

delivery (Robinson et al., 2001).

There is no conclusive evidence for a relationship between the various neurotransmitter systems, free or

total tryptophan levels, or cortisol levels and symptoms of postpartum depression (Llewellyn, Stowe, &

Nemeroff, 1997). However, Harris (1996) showed a minor association of postpartum depression and thyroid

dysfunction in thyroid antibody positive women.

Although it has been suggested that postnatal depression is caused by low levels of progesterone or

estrogen or high levels of prolactin, no consistent relationships have been found ( Harris, 1994; Hendrick,

Altshuler, & Suri, 1998).

A recent study by Bloch, Schmidt, Danaceau et al. (2000) tested the hypothesis that a subgroup of

women may have a differential sensitivity to reproductive hormones, and that in this group normal endocrine

events related to childbirth may trigger an affective episode. In order to test the hypothesis, they used a

scaled down model to simulate some of the hormonal events of pregnancy and childbirth. They tested two

groups of women, 8 of whom had a history of postnatal depression and 8 women without a history of

postnatal depression. Both groups of women were given a gonadotrophin releasing hormone agonist to

35

simulate the supraphysiological gonadal steroid levels of pregnancy over an eight week period and then these

were withdrawn to simulate childbirth.

Five of the eight women with a history of postpartum depression developed significant affective

symptoms during the withdrawal period; none of the 8 women who did not have a history of postnatal

depression experienced any mood symptoms during the withdrawal period. The authors concluded that these

data provided support for the involvement of estrogen and progesterone in the development of postnatal

depression in a subgroup of women.

Limitations

It should be noted that there are several methodological problems that hampered studies on the

biological basis of postpartum disorders (Robinson et al., 2001). Early researchers could not accurately assay

hormones, particularly free unbound plasma concentrations. Psychological rating scales differed between

studies, some were confounded by the normal physical symptoms of the puerperium, and as such were

obviously inappropriate measures of the maternal mental states. Blood sampling often took place at

inappropriate times, ignoring activities such as breastfeeding which can alter hormone levels. Seasonal

variations in hormones and circadian rhythms were often overlooked. Studies that examined one hormone

were inadequate because of complex endocrine interactions (Robinson et al., 2001).

As previously discussed, postpartum depression is best thought of as having multiple causal factors.

Even if some women are more susceptible to hormonal changes the role of environmental factors in the

development of the illness needs to be considered.

Obstetric Factors

Obstetric factors can include pregnancy related complications such as preeclampsia, hyperemesis,

premature contractions as well as delivery related complications, such as emergency / elective caesarean,

instrumental delivery, premature delivery and excessive bleeding intrapartum.

Obstetric Complications

In their meta-analysis, O’Hara and Swain (1996) included 13 studies comprising over 1350 subjects that

examined the effects of obstetric factors. They concluded that obstetric factors had a small effect (0.26) on

the development of postpartum depression.

More recent studies, (published after the meta analyses or those not included in the meta analyses) found

no overall statistically significant relationship between obstetric factors and postpartum depression.

For example, two large independent studies by Warner et al. (1996) (N=2375) and Forman et al (2000)

(N=5292), found no statistical relationship between obstetric complications and postpartum depression based

on both multivariate and univariate analysis.

36

Similarly, Johnstone et al. (2001) (N=490) reported no association between obstetric history, labour and

delivery, complications of pregnancy and infant details and postpartum depression. They did, however find a

nonsignificant trend between antepartum hemorrhage, forceps, multiparity and postpartum depression.

Josefsson et al. (2002), in their case control study (n=396), reported a similar nonsignificant association

between delivery complications and depression at 6 months postpartum.

Caesarean Section

The evidence relating to Caesarean section and postpartum depression suggests that there is no

association between the two variables. Warner et al. (1996) and Forman et al. (2000) found no significant

association between elective or emergency caesarean section and subsequent postpartum depression.

Johnstone et al. (2001) reported a nonsignificant trend between postpartum depression and caesarean section.

Boyce et al (1992) found a highly significant correlation between caesarean section and developing

postpartum depression at 3 months. They reported that women within their study who had an emergency

caesarean section had more than six times the risk of developing postpartum depression. These results were

supported by Hannah et al. (1992) who found a strong association between caesarean section and postpartum

depression at 6 weeks.

It is highly probable that the positive findings reported merely reflect statistical trends. Within such

large samples, one would expect by probability alone to achieve statistically significant results for 1 in 5

tests. However, when the results from the meta-analysis and a further 9,000 subjects are considered there is

no significant relationship between Caesarean section and the onset of postpartum depression.

Unplanned / Unwanted Pregnancy

Beck (1996) examined the effects of an unplanned or unwanted pregnancy and developing postpartum

depression. She included the results from 6 studies that comprised 1200 subjects, and found a small effect

size. These results were supported by Warner et al. (1996) who found a significant relationship between

unplanned pregnancy and depression at 6 weeks postpartum in a sample of 2375 women.

Unplanned or unwanted pregnancy as a risk factor for postpartum depression should be interpreted very

cautiously. It does not measure the woman’s feelings towards the growing fetus but merely the circumstances

in which the pregnancy occurred.

Breast Feeding

The evidence relating to breastfeeding as a potential risk factor is equivocal. Warner et al. (1996) found

that not breastfeeding at 6 weeks postpartum was significantly associated with postpartum depression

(N=2375). Hannah et al. (1992) supported these findings in a sample of 217 women. However, Forman et al.

(2000) (N=5292) did not find any relationship between not breastfeeding and postpartum depression.

37

The reasons for the equivocal findings reported between breastfeeding and the onset of postpartum

depression may reflect non-illness related factors, such as the woman’s preference or hospital policy rather

than an aetiological relationship.

Summary

In summary, the evidence suggests that obstetric factors make a small but significant contribution to the

development of postpartum depression. Despite the fact that most of the studies were prospective, self

reported, multi site sampling with large sample sizes, the timing of the evaluation of postpartum depression

differed between studies. O’Hara and Swain (1996) indicated that using relatively short time frames (e.g. 2

weeks) had significant effects on the strength of the relationship between putative risk factors and

postpartum depression.

However, there was heterogeneity between the methods of assessment of depression. Those studies that

diagnosed depression using interview methods found a weak association between obstetric complications,

but depression assessed through self-report measures was moderately related to these factors. These findings

suggest that while higher level of obstetric complications may be weakly associated with a diagnosis of

postpartum depression, they are moderately associated with higher levels of self reported depressive

symptomatology.

One must be very cautious when interpreting the effects of obstetric factors in developing postpartum

depression. Some of the variables measured may not be truly independent but rather influenced by

extraneous variables. For example, the number of Caesarean sections performed can vary within a hospital

because of consultants’ differing clinical views as to when the procedure is appropriate. The number can

then differ between hospitals, regions or provinces, and certainly between countries. In South Africa and

Australia for example, women can request delivery by Caesarean section which is not the case within the

United Kingdom. Consequently, the rates of Caesarean sections differ greatly between these countries.

Similarly, rates of breastfeeding or attitudes towards breastfeeding may differ within cultures and countries.

Therefore the results may be reflecting trends within the sample rather than a true relationship between

postpartum depression and obstetric variables.

Clinical Factors

Clinical factors relate to variables such as having previously experienced psychiatric symptoms, having

a family history of psychiatric illness, as well as measures of affect during pregnancy.

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Previous History of Depression

O’Hara and Swain’s (1996) meta analyses included 14 studies of approximately 3000 subjects which

examined the mother’s previous psychiatric history and postpartum depression. Beck’s (2001) meta-

analyses included 11 studies which examined approximately 1000 subjects.

The results of both meta-analyses found that a previous history of depression was a moderate to strong

predictor of subsequent postpartum depression. Subsequent studies consistently report that women with a

previous history of postpartum depression are at increased risk of developing postpartum depression

(Johnstone et al., 2001; Josefsson et al., 2002).

Family History of Depression

O’Hara and Swain (1996) combined data from 6 studies (approximately 900 women) to evaluate the

association between a family history of depression and women’s experience of postpartum depression.

The results showed no association between family history and postpartum depression. It was not a

significant predictor of postpartum depression within the samples (δ = 0.05, 95% CI –0.06 / 0.16). (Note: this

finding does not apply to postpartum psychosis where family history is a significant predictor of postpartum

psychosis). However, Johnstone et al. (2001) did find an increased risk of postpartum depression in 490

women with a family history of psychiatric illness.

One of the difficulties in establishing a positive family history of mental illness is that it requires the

subject to be aware of relatives with psychiatric problems, and for them to be willing to disclose that

information. It may be that there is relationship between family history and postpartum depression but the

methods of eliciting accurate information are not available at present.

Mood During Pregnancy

O’Hara and Swain (1996) included 13 studies comprising over 1000 subjects for their analyses, whilst

Beck included data from 21 studies which included over 2300 subjects.

The results found that depressed mood during pregnancy was a moderate – strong predictor of

postpartum depression. These results have been replicated in a number of subsequent studies (Johnstone et

al., 2001; Josefsson et al., 2002; Neter et al.,1995).

O’Hara further examined the relationship and found the association between depression during

pregnancy and postnatally when assessed via self-report was stronger (δ = 0.84; 95% CI 0.75 / 0.93) than the

relationship when assessed via an interview (δ = 0.39; 95% CI 0.22 / 0.56).

Prenatal Anxiety

A relationship had previously been reported between measurable anxiety during pregnancy and the level

of postpartum depressive symptoms (Hayworth et al., 1980; Watson et al., 1984).

39

These findings were supported by Beck who analysed the results of 4 studies, a total of 428 subjects,

and found anxiety to be a moderate predictor of postpartum depression.

O’Hara and Swain (1996) analyzed the results of 5 studies, comprising nearly 600 subjects and also

found that anxiety during pregnancy was a strong-moderate predictor of subsequent depression following

childbirth. These findings were supported in the subsequent studies by Johnstone et al. (2001) and Neter et

al. (1995) who found that higher levels of anxiety strongly predicted levels of postpartum depressive

symptomatology.

Summary

There’s little question that past history of psychopathology puts women at risk for depression in the

postpartum period. The average effect size is one of the largest for the risk factors of postpartum depression.

Consistent with the findings related to previous psychiatric history, depressed mood and anxiety during

pregnancy were also found to be a significant predictor of postpartum depression, particularly when indexed

by a self-report measure.

These findings are important because they indicate that dysphoric mood during pregnancy is not just

associated with dysphoric mood after delivery but with the clinical syndrome of postpartum depression as

well. These findings are consistent across studies and should be taken as important risk factors for the

development of postpartum depression.

Psychological Factors

Psychological Constructs

O’Hara and Swain (1996) compared maternal personality characteristics within studies to examine

whether they were associated with postpartum depression.

Neuroticism

Neurotic disorders can be defined as psychological disorders that are usually distressing but allow one to

think rationally and function socially. The neurotic disorders are usually viewed as ways of dealing with

anxiety. The term ‘neurotic’ is no longer used within psychiatric classification systems, although it is

commonly included in personality questionnaires as a measure of psychological distress.

Neuroticism was measured within 5 studies in over 550 women antenatally and found to be a weak to

moderate predictor (δ = 0.39; 95% CI 0.21 / 0.57) of postpartum depression (O’Hara & Swain, 1996).

These results have been replicated in subsequent studies. Lee et al. (2000) found that elevated scores on

neuroticism were significantly associated with women with postpartum depression. Johnstone et al. (2001)

found that women who were defined as ‘being nervy’, ‘shy-self-conscious’ or a ‘worrier’ through

40

questionnaires, were significantly more likely to develop postpartum depression. These are more modern

terms for psychological constructs similar to neuroticism.

Cognitive attributional style

Cognitive attributional style was also measured as a predictor of postpartum depression. Barnett and

Gotlib (1988) discuss how negative cognitions are good indicators of depression, and that depressive

attributions coincide with a depressed mood.

O’Hara and Swain analyzed 13 studies of over 1300 women and found that a negative cognitive

attributional style was weakly related to postpartum depression (δ0.24, 95%CI 0.18 / 0.31).

Summary of Clinical Factors & Psychological Constructs

The effect between neuroticism, assessed during pregnancy, and subsequent postpartum depression is

clear. O’Hara and Swain found that the effect was more pronounced when depression was defined as a

syndrome and was assessed through a clinical interview.

In contrast, a negative cognitive attributional style was more strongly related to high levels of depressive

symptomatology when assessed through self-report.

O’Hara and Swain highlight that these findings, together with those regarding past history of

psychopathology and depression during pregnancy, strongly suggest that there is a continuity of psychiatric

disturbance that extends back many years before a woman’s pregnancy and into the postpartum period. This

disturbance may be chronic or episodic. It may reflect disturbance in which the morbidity is relatively minor

or very severe. The question that remains is the extent to which, or whether, childbearing per se affects the

timing or severity of postpartum disturbance.

Social Factors

Life Events

The relationship between life events and the onset of depression is well established (Brown & Harris,

1978). Experiences such as the death of a loved one, relationship breakdowns or divorce, losing a job or

moving home are known to cause stress and can trigger depressive episodes in individuals with no previous

history of affective disturbance.

Pregnancy and birth are often regarded as stressful life events in their own right, and the stressfulness of

these events may lead to depression (Holmes & Rahe, 1967). However, some researchers have studied the

effects of additional stressful life events that women experience during pregnancy and the puerperium. These

events, thought to reflect additional stress at a time during which women are vulnerable, may play a causal

role in postpartum depression.

41

Paykel et al (1980), using a retrospective design, found that negative life events classified as moderate to

severe were associated with increased probability of being diagnosed as clinically depressed.

O’Hara, Rehm and Campbell found that high levels of life events from the beginning of pregnancy until

about 11 weeks postpartum were associated with higher levels of depressive symptomatology and a greater

likelihood of being diagnosed with postpartum depression (O'Hara, Rehm, & Campbell, 1982; O'Hara,

Rehm, & Campbell, 1983).

Hopkins, Campbell and Marcus (1987) found no association between life events and postpartum

depression. At least two other large studies have not found an association between life events and postpartum

depression (Holmes et al., 1967; Kumar et al., 1984).

One of the difficulties of assessing a possible relationship between life events and the onset of

depression postpartum is the study design. Retrospective collection of data may lead to over reporting of life

events as subjects (perhaps subconsciously) try to link a stressful event as a possible cause of the illness. The

prospective collection of data eliminates this source of bias, as the outcome of postpartum depression is not

known a priori.

In the recent meta-analyses, O’Hara and Swain took values from 15 studies, comprising data on over

1000 subjects that had prospectively recorded data on life events. They found a strong-moderate relationship

between experiencing a life event and developing postpartum depression (δ = 0.60, 95% CI: 0.54 / 0.67).

However, there was heterogeneity between studies which related to where the study was conducted:

studies undertaken in Britain and North America showed strong associations between postpartum depression

and recent life events, while Japanese studies showed a nonsignificant association. It is not clear why this

should occur. The more recent study conducted by Lee et al. (2000) in Hong Kong did not find an

association between life events and postpartum depression.

The method used to assess depression also explained heterogeneity of findings: interview based

assessments demonstrated a moderate relationship with life events while self report evaluations yielded a

significantly stronger relationship. The findings show that stressful events, even though they occur during

pregnancy and not in the puerperium, are clear risk factors for developing postpartum depression.

Beck (2001) used a less rigorously defined measure of ‘life stress’ to assess studies which measured

perceived stress within pregnancy and the early puerperium. She included 16 studies of over 2300 subjects

and found a moderate relationship between perceived life stress and postpartum depression. Higher levels of

perceived life stress were associated with postpartum depressive symptomatology.

Social Support

Receiving social support through friends and relatives during stressful times is thought to be a protective

factor against developing depression (Brugha et al., 1998) and several earlier studies have evaluated the role

of social support in reducing postpartum depression.

42

Social support is a multidimensional concept. Sources of support can be a spouse, relatives, friends or

associates. There are also different types of social support, for example informational support (where advice

and guidance is given), instrumental support (practical help in terms of material aid or assistance with tasks)

and emotional support (expressions of caring and esteem).

Researchers have also examined the effects of perceived support (a person’s general perception or belief

that people in their social network would provide assistance in times of need) and received support (where

supportive exchanges may be directly observed or measured by asking people). Received support is complex

and multidimensional, as one needs to measure both the quantity of support given (i.e. the frequency of

supportive acts, number of network members) and also the quality of the support received (Collins et

al.,1993; Dunkel-Schetter & Bennett, 1990; House & Kahn, 1985; Neter et al., 1995).

Studies have consistently shown a negative correlation between postpartum depression and emotional

and instrumental support (Beck, 1996a; Menaghann, 1990; Richman et al., 1991; Seguin et al., 1999). Two

recent studies have found that perceived social isolation (or lack of social support) was a strong risk factor

for depressive symptoms postpartum (Forman et al., 2000; Seguin et al., 1999).

However, there may be differences between perceived and received social support. Logsdon et al (2000)

studied social support among African-American low income pregnant women. Although she found a

significant relationship between perceived support and depressive symptomatology following delivery, there

was no relationship between received support and postpartum depression. This confirmed the findings of

earlier studies.

O’Hara, Rehm and Campbell (1983) studied perceived social support and found that depressed women

reported that their spouse was deficient in providing instrumental and emotional support following delivery.

However, these women did not identify their spouse as being less supportive during pregnancy any more

than nondepressed women. To a lesser degree, friends and parents of the depressed women were also

perceived as being less supportive during the puerperium, but not during the pregnancy. These results were

confirmed in a second study (O'Hara, 1986).

Cutrona (1984) found that several dimensions of perceived social support assessed during pregnancy

were predictive of the level of postpartum depressive symptoms. Surprisingly, the strongest predictor

concerned the availability of companionship and feeling of belonging to a group of similar others, rather than

the quality of intimacy with the husband.

O’Hara and Swain (1996) examined 5 studies in which overall levels of social support were measured

during pregnancy, based on over 500 subjects. They found that there was a strong negative relationship

between social support and postpartum depression (δ = -0.63; 95% CI –0.75 / -0.51). This suggests that

women who do not receive good social support during pregnancy are more likely to develop postpartum

depression. This concept was confirmed in a recent study which argued that receiving informational support

43

from a large number of social network members was protective against postpartum depression (Seguin et al.,

1999).

In order to try and further examine the concept of social support, O’Hara and Swain specifically looked

at perceived support from the baby’s father. They found a moderate strength relationship (δ = -0.53; 95% CI

–0.67 / -0.39) however there was heterogeneity in findings from studies dependent upon how depression was

assessed.

They concluded that poor support from the baby’s father, per se, was not significantly associated with

being diagnosed with postpartum depression however poor support was strongly negatively related with the

severity of depressive symptoms.

Summary

Social support, as it is manifest during pregnancy, is a relatively potent risk factor for postpartum

depression, particularly in the form of high levels of depressive symptomatology. The one study that

assessed overall social support during pregnancy and used an interview based depression outcome found a

very strong association between social support and depression.

Both overall social support during pregnancy and support from the baby’s father, in particular, were

associated with high levels of postnatal depressive symptomatology.

Studies have consistently found differences between perceived and received social support in women

with postpartum depression. These differences may be accounted for, in part, by the fact that depressed

individuals tend to view everything more negatively, including their perceptions of level of support.

The majority of studies have focused on cross sectional samples of pregnant women, however there may

be special groups for whom social support may be pertinent. For example, there is a dearth of work

examining the role of social support within low income groups (Lee et al., 2000; Logsdon et al., 2000;

Neter et al., 1995; Seguin et al., 1999). Similarly, the effects of social support among Aboriginal and

immigrant women is an area which needs further research.

Psychosocial Aspects of Childbearing

The effects of parenthood on all aspects of the mother’s psychosocial functioning should not be

underestimated. Robinson and Stewart (2001) discuss how, in many cases, the family system must be

reorganized, and many couples adopt more traditional roles. The mother usually tends to do the greater share

of parenting tasks, and the parents must decide how their new roles will affect their previous work patterns

and implement the necessary changes. With the added burden of childcare, the relationship between the

partners often suffers, and there is less time for socializing. A supportive relationship with the father can help

mitigate the stresses of being a new mother. These stresses should be borne in mind when evaluating the role

of factors in the development of postpartum depression.

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Marital Relationship

Several well designed studies (Braverman & Roux, 1978; Kumar et al., 1984) have reported an

increased risk of postpartum depression in women who experience marital problems during pregnancy.

Hopkins et al.(1987) however failed to confirm this finding. It has been mentioned previously that women

with postpartum depression perceived their husbands to be less supportive than women who were not

depressed, but these differences were apparent only postpartum and not during pregnancy (O'Hara, 1986;

O'Hara et al., 1983).

Marital relationship was measured between studies using a variety of different instruments, the

limitations of which need to be briefly discussed. The range of measurement went from a simple Likert scale

on which women indicate their level of satisfaction with the relationship, to standardized measures such as

the Dyadic Adjustment Scale (DYAS) (Spanier, 1976). The assessment could take place during an interview

or via a self-report design.

The fact that the meta-analyses were based on data measured pre partum eliminates potential reporting

bias. It was previously found that women with postpartum depression rated their husbands as less supportive,

however it is difficult to know whether their depressive symptomatology negatively influenced their

perceptions of their relationship. These results are free from such bias as the measures were taken prepartum.

Global measures

Studies which assessed marital relationship using more global measures such as Likert scales or through

open questions were assessed in both meta analyses. Beck included 14 studies comprising over 1500

subjects, while O’Hara and Swain included 8 studies of over 950 subjects.

Beck found a moderate association between poor marital relationship and postpartum depression, whilst

O’Hara and Swain reported a small negative relationship.

It was interesting that differing methods of assessment produced different effect sizes. Marital

relationship assessed via interviews was not as predictive as when measured via self -report. The reason for

this is unclear, but may relate to reluctance to discuss the nature of the relationship with an interviewer, but

through the anonymity of a questionnaire it is easier. It could also reflect increased sensitivity within

questionnaire measures.

DYAS.

O’Hara and Swain (1996) examined the association between mother’s prepartum relationship with their

spouse, focusing on studies which used the Dyadic Adjustment Scale (DYAS). The DYAS is a self-report

measure which has proven psychometric properties, and is a standardized measure of the quality of the

marital relationship.

45

The results from 6 studies, on over 1100 subjects which used the DYAS indicated a small but significant

negative relationship between marital satisfaction on the DYAS and incidence of PPD (δ = -0.13; 95% CI –

0.20 / -0.06).

Summary

Marital adjustment assessed during pregnancy with a standard self report measure (DYAS) is much

more predictive of postpartum depression than by interview.

Marital adjustment assessed with more global scales showed the opposite pattern. O’Hara and Swain

argue that this could be because a psychometrically refined measure such as the DYAS may be a more

sensitive predictor of depression than a global rating scale. However, experiencing difficulties in the marital

relationship, or having a poor marital relationship during pregnancy is a predictor of subsequent postpartum

depression.

Socioeconomic Status

The role of socioeconomic status in the aetiology of mental health disorders and depression has received

much attention. Socioeconomic deprivation indicators such as unemployment, low income and low education

have been cited as risk factors in mental health disorders (Bartley, 1994; Jenkins, 1985; Patel et al., 1999;

Weich et al., 1997; World Health Organization, 2001). Recent studies from North America, Latin America

and Europe reported that depression is more common among poorer countries (World Health Organization,

2001).

Socioeconomic deprivation has also been studied in the aetiology of postpartum depression. Beck

(2001) examined 8 studies of 1732 subjects and found a small effect (0.19 - -0.22) between socioeconomic

status and postpartum depression. However, it is unclear which indicators of socioeconomic status were

included in this meta-analysis.

O’Hara and Swain (1996) examined 14 studies of over 1650 subjects and also reported a small effect (-

0.141). They concluded that indicators such as low income, mother’s occupation, and being of lower social

status had a small but significant predictive relationship to postpartum depression. However, other

sociodemographic variables including marital status, pregnancy employment status and parity did not show

any significant relationship to postpartum depression.

Recent studies which were not included in the meta-analyses found that unemployment and financial

strain were significantly associated with postpartum depression (Lee et al., 2000; Patel et al., 2002; Seguin

et al., 1999; Warner et al., 1996).

Lee (2000), Patel (2002) and Seguin (1999) specifically studied low income populations within India,

China and Canada respectively and found that financial strain was an important risk factor in postpartum

depression within these populations.

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Summary

In summary, there is evidence that low socioeconomic status has a small effect on the development of

postpartum depression. However, one of the methodological limitations in the literature is the different

criteria used to determine indicators of ‘low income’.

In addition, most studies have focused on relatively homogenous samples of middle to upper class

women, with few studies examining the relationship between socioeconomic indicators and postpartum

depression among lower socioeconomic groups within both developed and developing countries.

Infant Variables

By definition, variables relating to the infant can only be measured postpartum. As such their predictive

power is subject to bias, particularly in relation to the objectivity of the mother’s reports.

It has previously been reported that child related factors were associated with postpartum depression.

Cutrona (1983) reported that higher levels of childcare related stressors were associated with higher levels of

depressive symptomatology, while Hopkins, Campbell and Marcus (1987) found that having a difficult baby

or a baby with neonatal complications was associated with a diagnosis of postpartum depression.

Beck (2001) studied two variables related to the infant, child temperament and childcare stress. She

found that childcare stress and having an infant with a difficult temperament were moderately predictive of

postpartum depressive symptomatology (N=789).

It has been found that mothers suffering from postpartum depression give more negative descriptions of

their children than control mothers and report more behavioural problems in their infants (Murray, 1988).

Therefore, the mothers’ symptoms may be a source of bias in the reporting of infant characteristics.

Factors not Associated

The results of the meta-analyses by O’Hara and Swain (1996) and Beck (2001) found that the following

were not significantly associated (i.e. the confidence interval contained 0) with the development of

postpartum depression:

• Maternal age (O’Hara & Swain, 1996: 26 studies, N >10,000)

• Level of education (10 studies, N >7,000)

• Parity (7 studies, N >2,000)

• Length of relationship with partner (6 studies, N > 800)

• Sex of child * (15 studies, N > 8,000)

* Sex of Child - Studies conducted within Western societies have found no association between the sex

of the child and postpartum depression. However, recent studies provide evidence from India (Patel et

al.,2002) (n=171) and China (Lee et al.,2000) (n=220) which suggest that spousal disappointment with the

sex of the baby, specifically if the baby is a girl, is significantly associated with developing postpartum

47

depression. Therefore, the parent’s reaction to the sex of the baby may be a potential risk factor for

postpartum depression within certain cultural groups.

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Table 1-7. Summary of Select Primary Studies Not Included in Meta-Analyses

Author, Year, Country

Study Design Population Sampled

Measures & Timing of Assessment

Contributing Factors Examined

Significant Factors / Outcome

Limitations / Comment

Boyce, 1992, Australia

Prospective Using questionnaire Community based Follow- up at one, three and six months postpartum

192 women in antenatal clinic in first trimester 188 women divided into 3 groups by method of delivery: 21 - emergency caesarean section; 49 forceps delivery;118 spontaneous vaginal delivery

1st trimester - The Interpersonal sensitivity Measure. Eysenck Personality Inventory (EPI). The Intimate Bond Measure. The Beck Depression Inventory (BDI). Edinburgh Postnatal Depression Scale (EPDS) was used at 1, 3 & 6 months after delivery.

Emergency caesarean section Forceps delivery Spontaneous vaginal delivery

Emergency caesarean section at three months postpartum significantly associated with PPD.

Sampling bias, no recruitment date information homogeneous and small sample group. No information on previous or family history of psychiatric illness. Reasons for the emergency caesarean section not discussed and may be risk factors for depression.

Patel, 2002, India

Prospective Follow-up Questionnaires Community based

270 pregnant women recruited during their third trimester from a district hospital in Goa, India.

Interview at recruitment with GHQ (Konkani version), 6-8 weeks, and 6 months after childbirth. EPDS (Konkani version) was used at 6-8 weeks and 6 months follow-up. Semistructured interview for sociodemographic data, obstetric history, gender-based variables

Antenatal and postnatal depression Obstetric history Economic and demographic characteristics Gender-based variables (preference for male infant, presence of marital violence).

Significant Factors: Psychological morbidity during the antenatal period. Economic deprivation and poor marital relationships Gender of the infant

New data from India Prospective Interesting cultural finding regarding gender of child Validation of EPDS which allows comparison between countries

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Author, Year, Country

Study Design Population Sampled

Measures & Timing of Assessment

Contributing Factors Examined

Significant Factors / Outcome

Limitations / Comment

Lee, 2000, China

Prospective longitudinal study Community based Questionnaires and interview

220 Chinese women were consecutively recruited from University teaching hospital, Hong Kong between 1996 & 1997.

The clinician-administered Structured Clinical Interview for the Diagnostic and Statistical Manual of Mental Disorders (SCID-NP). Interview, BDI and GHQ on the second day after delivery 6 weeks postpartum - SCID-NP.

Sociodemographics Socio-economic status Previous medical, gynecologic and obstetric history Circumstances during pregnancy Perinatal factors Psychosocial factors

Significant Factors: Depression during pregnancy, elevated depression score at delivery, prolonged postnatal 'blues' Temporary housing accommodation, financial difficulties, abortions, past psychiatric disorders, elevated neuroticism score Spouse disappointment with the gender of the newborn.

‘Prolonged blues’ is a measure of PPD so result not valid. New data from Hong Kong Allows for cultural comparisons Gender of child findings interesting regarding culture

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Author, Year, Country

Study Design Population Sampled

Measures & Timing of Assessment

Contributing Factors Examined

Significant Factors / Outcome

Limitations / Comment

Johnstone, 2001, Australia

Prospective Multi-site Urban and rural community sample Questionnaires

504 women were recruited antenatally from participating hospitals. Complete data were obtained from 490 women between 1995 &1996.

EPDS was used eight weeks after delivery. Population-based surveillance system: to examine obstetric factors Postnatal questionnaire: sociodemographic information Structured Clinical Interview for DSM-III-R (SCID): personality

Obstetric risk factors: complications of pregnancy, labour and delivery, infant details. Sociodemographic data Personality Psychiatric history Recent life events

None of the obstetric variables were significantly associated with PPD. Significant risk factors: Sociodemographic variables Personality Psychiatric history Recent life events

Comparatively small sample size Population based system reduces self-report bias Interpretation of personality data may be limited

Josefsson, 2002, Sweden

Prospective Case-control Multi-site Community based Questionnaire

Cohort of 1489 pregnant women assessed for depression at 6-8 weeks postpartum during 1997-1999. 132 women who scored >10 on EPDS at 6-8 weeks postpartum selected as index group. Control group comprised 264 women without depressive symptoms as assessed by EPDS.

EPDS (Swedish version) was administered at 6-8 weeks and 6 months after delivery.

Sociodemographic status Pregnancy, and perinatal events Previous medical, gynecologic and obstetric history

Significant Risk Factors: Pregnancy complications, Sick leave during pregnancy and a high number of visits to the antenatal care clinic. Antenatal depressive symptoms and PPD were significantly correlated. No significant association between parity, sociodemographic data, mode of delivery and delivery complications.

This study includes previous medical, gynecologic and obstetric history as a risk factor which is novel. Prospective design reduces bias Adequately powered sample. Multi-centre, prospective, case-control design – very well designed.

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Author, Year, Country

Study Design Population Sampled

Measures & Timing of Assessment

Contributing Factors Examined

Significant Predictors / Outcome

Limitations/ Comments

Warner, 1996, U.K.

Prospective Questionnaires to identify women with postpartum depression

2375 women recruited from postnatal wards on two maternity units between 1993 & 1995. Completed screening questionnaire

The Edinburgh Postnatal Depression Scale (EPDS) was administered, six to eight weeks after delivery

Sociodemographic and obstetric risk factors: Unplanned pregnancy Sub fertility Primiparity Complicated pregnancy Caesarian section Mean birth weight Baby on special-care Not breast feeding (6 weeks)

Four independent variables were found to be significantly associated with an EPDS above threshold (> 12) Unplanned pregnancy Not breast-feeding Mother unemployed i.e. no job to return to following maternity leave Head of household unemployed

High proportion of women had complications No data on previous or family psychiatric history Factors not measured antenatally therefore less predictive power Findings may be reflecting characteristics of the sample rather than risk factors Variables influenced by extraneous variables

Forman, 2000 Denmark

Prospective Community based Follow-up using questionnaires

Cohort of women attending antenatal program at Aarhus University Hospital 5252 women who gave birth between 1994&1995, completed all follow-up questionnaires

The EPDS administered 4 months after delivery 4 months postpartum : psychological distress measured by GHQ

Sociodemographic factors Marital status Working status History of psychiatric disease Family history of psychiatric disease Level of psychological distress in 3rd trimester Perceived social isolation Antenatal events including obstetric & gynecological factors

Significant predictors of PPD: Psychological distress in late pregnancy Perceived isolation during pregnancy High parity Positive history of psychiatric illness

High rate of non-responders, who scored higher on risk factors – sample bias Results pertain to women with lower risk factors and who were more motivated to respond/complete follow-up questionnaires Antenatal factors rated, higher predictive power

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Contributing Factors to the Development and Recovery from Postpartum Depression: Metasynthesis

of Qualitative Studies

The use of qualitative methodologies within health studies enables the researcher to gain an ‘insider’s

perspective’ of illness, which would be impossible through quantitative methods. A number of studies have

employed such methods in order to increase our level of understanding of the experience of living with, and

through, postpartum depression.

Beck (2002) recently published a metasynthesis of 18 studies of postpartum depression, published

during the 1990s, which used qualitative methodologies. A metasynthesis refers to “the theories, grand

narratives, generalizations, or interpretive translations produced from the integration or comparison of

findings from qualitative studies” (Sandelowski, Docherty, & Emden, 1997). The ‘meta’ refers to translating

qualitative studies into each other, or interpreting the data.

Beck identified four overarching themes or perspectives involved with postpartum depression:

1. Incongruity between expectations and reality of motherhood

2. Spiraling downward

3. Pervasive loss

4. Making gains.

She stressed that mothers can move back and forth between these differing perspectives, and they can be

in more than one at any time. Within the context of the metasynthesis, these factors were highlighted by the

women as: i) contributing to the onset of the illness and ii) aiding in their recovery. Each of these

perspectives shall be presented and discussed in turn, with reference made to the original studies where

appropriate.

Incongruity Between Expectations and Reality of Motherhood

Nicolson (1990) has written extensively about the ‘dangerous myths’ operating among both

professionals and lay people which equate becoming a mother with total fulfillment and happiness. Eight of

the 18 studies in the metasynthesis centred on the role that conflicting expectations and experiences of

motherhood played in the development of postpartum depression. Women held unrealistic expectations

which were shattered by their own experiences as mothers (Mauthner, 1999). They became disillusioned

with motherhood, as they perceived they had failed to fulfill their expectations of themselves as the ‘perfect

mother’ (Berggren-Clive, 1998).

Emotions of despair and sadness started the mothers’ spiral downward into postpartum depression. The

women in Berggren-Clive’s study described the incongruity between their expectations and reality of

motherhood in seven areas: labour and delivery, life with their infants, self as mother, relationship with

partners, support from their family and friends, life events and physical changes (Berggren-Clive, 1998).

53

Nicolson (1990) and Beck (2002) argue that because society perpetuates these myths of the perfect

mother, and motherhood as a totally fulfilling and happy experience, the women believed that no other

mothers shared their negative reactions to childbirth. Therefore, they viewed themselves as ‘bad’ or

‘abnormal’ mothers, which led to fear of moral condemnation and being labeled by others as failed mothers.

Mauthner (1998) identified 3 kinds of conflict in mothers’ narratives, all of which centred on their desire

to be the ‘perfect mother’. One area of conflict concerned how to care for their infant regarding topics such

as breastfeeding and being employed. The second set revolved around women’s depression and unhappiness,

which was in direct conflict with their expectations that they would be happy with their infants. The third

concerned expectations that they could cope with their new infants, when the reality was that they needed

help.

For each woman, the conflicts she experienced depended on what her notion of what makes ‘a good

mother’ and what aspects of motherhood were especially significant to her. Parity influenced the conflicts

that some of the women struggled with: the conflicts that the 12 first time mothers struggled with centred on

trying to live up to their image of the ‘perfect, ideal mother’ (Mauthner, 1999). In contrast, the 6 multiparas

were well aware that there was no such thing as the perfect mother and their conflicts revolved around trying

to live up to their expectations of being able to cope with their newest child.

It appears that cultural context can intensify these conflicting expectations and experiences of

motherhood. If there are high cultural expectations of motherhood, then this could exacerbate women’s

feelings of helplessness and being a bad mother. This may have particular relevance for women who are no

longer living in their home country and are separated from their immediate family who would usually

provide practical and emotional support during the postpartum period.

Spiraling Downward

Mothers began the downward spiral of postpartum depression as their feelings worsened. All 18 studies

in the metasynthesis addressed aspects of this downward spiral.

Emotional

The emotions did not include just depression and sadness (Wood, Thomas, Droppleman, & Meighan,

1997), but women covertly suffered through a myriad of emotions such as anger, guilt, being overwhelmed,

anxiety and loneliness. Some mothers also experienced obsessive thoughts or cognitive impairment and

contemplated harming themselves or their infants, which led to increased feelings of anxiety and guilt. The

women who admitted to thoughts of selfharm and suicide spoke about how suicide provided a glimmer of

hope ‘to the end of the nightmare’ and ‘the blackness’.

Isolation / Loneliness

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Women consistently talked about a profound sense of isolation and loneliness. They frequently felt

discomfort at being around others and their belief that no one really understood what they were experiencing

(Beck, 1992). They socially withdrew to escape a potentially critical world (Semprevivo, 1996).

Social factors appeared to modify the sense of isolation. Primiparas felt physically isolated from other

mothers, but multiparas had already developed a network of other mothers from their previous children

(Mauthner, 1995).

Depending on the reaction of their coworkers to the mothers’ return to employment, the mothers’ sense

of isolation could be increased or decreased. Some mothers valued the companionship of their work

colleagues but at the same time felt they were missing out on the network of mothers who stayed at home.

Others felt an increased sense of isolation because their colleagues disapproved of working mothers.

Guilt

Women lived with the burden of guilt for many different reasons: being a bad mother (Mauthner, 1995;

Mauthner, 1999; Mauthner, 1998) failure to be the perfect mother (Wood et al., 1997), and lack of an

emotional connection with their baby (Beck, 1996b; Sluckin, 1990). The mothers who thought about

harming their infants (Beck, 1992; Semprevivo, 1996) were so horrified by these thoughts that they were

consumed by guilt.

Pervasive Loss

Loss of control was identified as a central theme in 15 out of the 18 studies. The loss of control related

to all aspects of their life including thought processes, emotions, and relationships.

Nicolson’s (1999) study described how loss of autonomy and time were precursors to feeling out of

control because the women no longer had time to consider themselves or process their daily experiences.

This in turn led to a sense of loss of self, loss of their former self and a loss of identity.

Women discussed how the illness led to loss of relationships, with their partners, children and family

members (Morgan, Matthey, Barnett, & Richardson, 1997). Some women wanted their partners ‘to be able to

read their minds’ and take some initiative in helping them, whilst others felt that admitting their feelings was

a sign of personal inadequacy and failure as a mother (McIntosh, 1993). If they did admit to their feelings the

women also risked being misunderstood, rejected or morally condemned by their loved ones. Because

women with postpartum depression felt ‘different’ and ‘abnormal’ compared to other mothers, they withdrew

from these relationships and spoke of the difficulty about being surrounded by other mothers (Mauthner,

1995).

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Making Gains

Surrendering was a big part of the mother’s recovery from postpartum depression. The concept of

‘surrendering’ in this context meant realizing something was very wrong and they needed to get help.

Unfortunately, women’s initial interactions with health professionals caused more distress: women reported

that their concerns were ignored or minimized and feelings of disappointment, frustration, humiliation and

anger were commonplace.

In McIntosh’s study (1993) only 18 of the 38 women interviewed had sought help. The main reasons

that they gave included feeling embarrassed and ashamed, and the fear of being labeled as a ‘bad mother’

and the stigma associated with being ill at what should be a happy time.

Attendance at postpartum depression support groups created hope within the women as they realized

that they were not alone (Berggren-Clive, 1998) the women found solace in these groups (Beck, 1992). Their

feelings of isolation and loneliness were dissipated as they could identify with others and openly question the

ideals of motherhood they struggled to fulfill (Mauthner, 1995).

Reintegration & Change

Adjusting the unrealistic expectations that the mothers had for themselves was cited by most women in

Berggren-Clive’s study (1998) as one means of freeing themselves from the constraints they had imposed on

themselves. The women shifted expectations with respect to themselves as mothers, partners and family

members which was necessary in rebuilding self.

The mothers began to regain control of their lives as they recognized their needs and found ways of

meeting them. It was a slow, unpredictable process however and as the depression lifted, the women began to

mourn the lost time that they would not be able to recapture with their infants.

Many of the women described an increased sense of strength following their experience of postpartum

depression, as recovery involved acceptance or resolution of the conflicts they had experienced during their

transition to motherhood (Mauthner, 1998).

Summary of Metasynthesis of Qualitative Literature

The results from the metasynthesis show that there were a number of areas that the women highlighted

as contributing towards the development of their postnatal depression.

The majority of women found that the reality of motherhood was very different from their expectations.

They felt overwhelmed which in turn led to feelings of inadequacy as a mother and associated guilt that they

could not fulfill their social role.

The women also felt that they could not confide in their loved ones for fear of being labeled as a bad

mother, or moral condemnation. Feelings of isolation and that no one else could identify with their

56

experience were commonplace and added to the feelings of inadequacy. For some women this was

compounded by cultural expectations of motherhood, particularly if they were not in their home country.

As part of their recovery, women spoke about the positive effects of attending a support group – how it

created hope as they could identify with other women in a similar situation and have their experiences

normalized.

Women frequently did not admit to symptoms or seek help because of the stigma associated with being

ill, or because they did not recognize their feelings as pathological. Beck argues that health care professionals

have a responsibility to take an active role in alleviating the harmful myths surrounding motherhood that are

prevalent within society.

Summary of Risk Factors for Postpartum Depression

The puerperium is well established as a time of increased risk for the development of serious mood

disorders, although the prevalence of overall depression is similar to that of age and social class matched

women who have not born children in the previous year.

Postpartum depression is the most common complication of childbearing, affecting 10 – 15% of women,

and as such represents a considerable public health problem affecting women and their families. Research

studies have shown a number of risk factors to be associated with the development of postpartum depression.

All women are susceptible to developing depression following childbirth. However, women who have

one or more of the following factors have a significantly increased risk of experiencing the illness. All of

these factors, except measures of infant temperament and childcare stress, were measured antenatally to

reduce risk of bias and were found to be predictors of postpartum depression, even after controlling for

differences in assessment methods for depression, sampling frames and where the research was conducted.

All of these factors can be ascertained during pregnancy as potential risk factors, and high risk women

identified for close follow-up and possible interventions.

These are shown in order of magnitude below, as defined by Cohen’s effect size. That is, the strongest

down to the smallest predictors of postpartum depression. A summary of the studies which provided these

data are given in Tables 1-8 – 1-10 at the end of this chapter.

57

Strong to Moderate

Depression during pregnancy

Anxiety during pregnancy

Stressful recent life events

Lack of social support (either perceived or received)

Previous history of depression

Moderate

High levels of childcare stress

Low self-esteem

Neuroticism

Difficult infant temperament

Small

Obstetric and pregnancy complications

Cognitive attributions

Quality of relationship with partner assessed using DYAS.

Socioeconomic status

No effect

Ethnicity

Maternal age

Level of education

Parity

Gender of child (within Western societies)

The risk factors identified from quantitative studies are well established: they are methodologically

robust and have been replicated within numerous studies across different sample populations. However, it is

also useful to study the individual views of women who have experienced postpartum depression, as their

view may inform possible service provision and educational needs.

A meta-analysis of qualitative studies of postpartum depression found that women’s experiences of

motherhood differed from their expectations quite markedly. Many women felt overwhelmed which led to

feelings of inadequacy as a mother, and the associated guilt that they could not fulfill their social role.

58

It appears that cultural context may intensify these conflicting expectations and experiences of

motherhood. If there are high cultural expectations this could exacerbate women’s feelings of helplessness

and being a bad mother.

This may have particular relevance for mothers who are no longer living in their own country and are

separated from family who would usually provide practical and emotional support during postpartum period.

Lack of social support is a well established risk factor for postpartum depression, and immigrant women may

be at higher risk of depression because they are culturally and physically separated from their support

systems. Recent studies from India and China indicated that disappointment at having a baby girl may also

contribute to postpartum depression. Health care professionals should be aware that the gender of the child

may be an additional risk factor within some cultures.

Women frequently spoke of their sense of isolation; the feeling that no else could understand or could

identify with what they were going through. The women also felt that they could not confide in their loved

ones for fear of being labeled as a bad mother. However, as part of their recovery, women spoke about the

positive effects of attending a support group: how it created hope as they could identify with other women in

a similar situation and have their experiences normalized. This could also be culturally sensitive to alleviate

feelings of isolation that immigrant women may feel.

The stigmatization of mental illness remains a major problem: women frequently did not admit to

symptoms or seek help because of the stigma associated with being ill or because they did not recognize their

feelings as pathological.

Gaps in the Literature

The synthesis of literature on factors associated with developing postpartum depression identified

particular areas in which more work needs to be done.

Lower socioeconomic status is an established risk factor for non-puerperal depression. The experience

of pregnant women in low income populations, who may already be at higher risk of depression, is under

researched at present. Their interactions with, and access to, health care services, and opportunities for social

networks and support may differ significantly from higher income groups.

The rate of postpartum depression within the general population is 10-15%, however the rates in teenage

mothers have been reported to be as high as 26%. This group requires further study as there may be factors

which contribute to both teenage motherhood and subsequent depression.

The use of standardized assessment tools for depression may not be suitable with all cultural groups and

researchers need to be culturally sensitive. The experience of postpartum depression outside of a woman’s

home country requires further work. These women may be at higher risk because of lack of social support,

cultural expectations of motherhood and a reluctance to disclose psychiatric symptoms and receive care from

health professionals.

59

Conclusions

Although there is no archetypal model of a woman at risk of developing postpartum depression,

researchers have attempted to produce a ‘composite’ which is useful within a clinical framework (O'Hara et

al., 1996). Although an over-simplification, it is useful to portray the results from the synthesis of literature

on risk factors of postpartum depression.

Her clinical history may reveal previous experience of psychiatric illness, and she may have suffered

from depressive or anxious symptoms during pregnancy. She may be experiencing difficulties through

stressful life events and a poor marital relationship. She perceives that her partner, family and friends are not

as supportive as they could be (although this may not be true).

60

Table 1-8. Strong Predictors of Postpartum Depression

Predictor variable Total Number of Subjects

Level of Effect & Direction of New Data

Depression during pregnancy

O’Hara & Swain 1996 Beck 2001 Josefsson et al 2002 Johnstone et al 2001 Neter et al 1995

>1000 (13 studies) 2, 305 (21 studies) 132 probands 264 controls 490 108

STRONG / MODERATE Significant association, supporting findings Significant association, supporting findings Significant association, supporting findings Significant association, supporting findings

Anxiety

O’Hara & Swain 1996 Beck 2001 Johnstone et al 2001 Neter et al 1995

>586 (5 studies) 428 (4 studies) 490 108

STRONG / MODERATE Significant association, supporting findings Significant association, supporting findings Significant association, supporting findings

Life events

O’Hara & Swain 1996 Beck 2001 Lee et al 2000

>1015 (15 studies) 2324 (16 studies) 220

STRONG / MODERATE * *within Western societies but not Japanese samples Significant association, supporting findings No association with life events within Chinese sample

Social support

O’Hara & Swain 1996 Beck 2001 Forman et al 2000 Seguin et al 1999

> 521 (5 studies) 2692 (27 studies) 5292 68

STRONG / MODERATE Significant association, supporting findings Significant association, supporting findings Significant association, supporting findings

Previous history of depression

O’Hara & Swain Beck 2001 Joseffson et al 2002 Johnstone et al 2001

>2896 (14 studies) 991 (11 studies) 132 probands 264 controls 490

STRONG / MODERATE Significant association, supporting findings Significant association, supporting findings Significant association, supporting findings

61

Table 1-9. Moderate Predictors of Postpartum Depression

Predictor Variable Total Number of Subjects

Level of Effect & Direction of New Data

Neuroticism

O’Hara & Swain 1996 Lee et al 2000 Johnstone et al 2001

>552 (5 studies) 220 490

MODERATE Significant association, supporting findings Significant association, supporting findings

Childcare stress

Beck 2001

789 (7 studies)

MODERATE

Self-esteem

Beck 2001

570 (6 studies)

MODERATE

Infant temperament

Beck 2001

1,056 (10 studies)

MODERATE

Table 1-10. Small Predictors of Postpartum Depression

Predictor variable Total Number of Subjects

Level of Effect & Direction of New Data

Obstetric & Pregnancy complications

O’Hara & Swain 1996 Warner et al Forman et al Johnstone et al Josefsson et al Boyce et al 1992 Hannah et al 1992

>1366 (13 studies) 2375 5292 490 132 prob and 264 control 188 217

SMALL No statistical relationship found No statistical relationship found No statistical relationship found No statistical relationship found Significant association found with Caesarean Section Significant association found with Caesarean Section

Cognitive attributions

O’Hara & Swain 1996

>1318 (13 studies)

SMALL

Relationship with partner assessed using (DYAS)

O’Hara & Swain 1996

>1133 (6 studies)

SMALL

Socioeconomic status and income

O’Hara & Swain Beck Lee 2000, Patel 2002, Seguin 1999, Warner et al 1996

>1668 (14 studies) 1,732 (8 studies) Small studies

SMALL Small effect size reported supporting findings “Important” risk factor

62

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